Social Support and Chronic Kidney Disease: An Update

Social Support and Chronic Kidney Disease: An Update

Social Support and Chronic Kidney Disease: An Update Scott D. Cohen, Tushar Sharma, Kimberly Acquaviva, Rolf A. Peterson, Samir S. Patel, and Paul L. ...

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Social Support and Chronic Kidney Disease: An Update Scott D. Cohen, Tushar Sharma, Kimberly Acquaviva, Rolf A. Peterson, Samir S. Patel, and Paul L. Kimmel Social support is an understudied, yet important, modifiable risk factor in a number of chronic illnesses, including end-stage renal disease (ESRD). Increased social support has the potential to positively affect outcomes through a number of mechanisms, including decreased levels of depressive affect, increased patient perception of quality of life, increased access to health care, increased patient compliance with prescribed therapies, and direct physiologic effects on the immune system. Higher levels of social support have been linked to survival in several studies of patients with and without renal disease. Higher perceived spousal support among women on dialysis was linked to improved compliance and survival in subgroup analyses. Few studies have examined the impact of social support interventions in ESRD patients. Studies have been limited by small sample size, retrospective analyses, and lack of control populations. Given the potential link with survival, a large, prospective, randomized controlled trial is needed to evaluate the impact of a social support group intervention in ESRD patients. © 2007 by the National Kidney Foundation, Inc. Index Words: Quality of life; depression; compliance; marriage; survival

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he burden of chronic disease in the United States is extensive. The number of Americans living with chronic diseases is estimated to exceed 90 million, with an economic impact of nearly 1 trillion dollars per year.1 Chronic kidney disease may arguably affect 19.2 million Americans.2 Almost 336,000 end-stage renal disease (ESRD) patients were treated with dialysis in 2004, and more than 136,000 patients had renal transplants.3 Costs for the ESRD program exceeded 18 billion dollars in Medicare health-care expenditures in 2004.3 In an effort to minimize these costs, research, in recent years, has begun to focus more on the prevention of progression and complications of chronic disease.1,4 Focusing on modifiable risk factors, such as poor nutrition, depression, and lack of social support, holds the promise of having an impact on outcomes in ESRD patients.

“Cognitive support” refers to the support that additional information or knowledge provides an individual.9,10 “Emotional support” refers to an individual conveying his or her concerns and feelings for another person, which can lead to increased perception of social support.9,10 “Materials support” refers to the provision of particular “goods and services,” which leads to increased social support.9,10 The link between a lack of social support and mortality has been well established, with those patients with lower levels of support at increased risk for death.5,11 This relation has been demonstrated in a wide range of populations, with some variation in outcomes between specific ethnic groups and genders.5,11 The suggestion has even been made that the mere presence of any of these relations may

Definition

From the Departments of Medicine, Nursing Education, and Psychology, George Washington University, Washington, DC. Scott Cohen is supported by a research fellowship from the National Kidney Foundation. Address correspondence to Paul L. Kimmel, MD, Division of Renal Diseases and Hypertension, Department of Medicine, George Washington University Medical Center, 2150 Pennsylvania Avenue NW, Washington, DC 20037. E-mail: pkimmel@ mfa.gwu.edu © 2007 by the National Kidney Foundation, Inc. 1548-5595/07/1404-0005$32.00/0 doi:10.1053/j.ackd.2007.04.007

Social support refers to the intricate network in which a person may give and receive information and aid and have emotional needs met.5-7 This network includes interpersonal relationships with spouses, family, friends, or other people, as well as participation in religious, occupational, social, and community organizations.5,8 Social support has been classified into 3 major types.9,10

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have a more protective effect on health than living in complete social isolation does.11 Despite the evidence favoring a role for social support in reducing the morbidity and mortality among patients with chronic illnesses, the mechanisms by which it influences health are still not completely understood.5-6,12-14 Several of the mechanisms that have been proposed include improvements in aid and access to care, improvement in symptoms of depression and extent of anxiety, better adherence to therapy, and direct physiologic effects.6-8,12-14 Evidence suggests that social support may affect outcomes through these mechanisms in many chronic diseases, including diabetes mellitus, cardiovascular disease, human immunodeficiency virus infection, hepatitis, and cancer.13,15-19 Of particular interest, we have demonstrated relations between social support and depression, quality of life, compliance, and survival in patients with ESRD.20-22 This article will provide an overview of recent evidence since our previous review,7 and examine social support and its relation to aid and access to care and its role in ameliorating depressive symptoms, compliance, and survival in patients with chronic disease and ESRD.

Social Support and Interaction with Chronic Disease Social Support and Access to Health Care Understanding the relation between social support and access to care first requires a brief exploration of the processes by which patients access health care. For an individual to have access to health care, the person must be able to obtain entry, gain access, and locate providers who can meet his or her needs.23 The process of obtaining access to health care is analogous, in some ways, to the process of traveling to another country. Just as an individual must possess a passport and visa to be granted permission to enter the country, an individual seeking access to health care must first possess the necessary documentation (Medicaid, Medicare, private insurance, etc) to enter the health-care system quickly and easily. Without such documentation, individ-

uals may be forced to rely on hospital emergency departments for routine care instead of primary-care providers better equipped to provide ongoing care. Once a traveler obtains entry to a country, he or she is faced with the task of accessing the ultimate destination. Likewise, individuals seeking health care must be able to get to the place where health care is provided. Without resources such as reliable, affordable transportation, gaining access to health care may be extremely difficult for patients. The final step in the process of obtaining access to health care involves locating providers who can meet the patient’s needs within the context of a relationship built on trust and communication.23 A traveler can gain entry to another country and travel to the ultimate destination within that country, but if no one at the destination speaks the traveler’s language and vice versa, the trip is likely to be a frustrating one. Likewise, if patients are unable to find providers who can communicate with them and meet their needs, they do not truly have access to the health care they require. Use of the metaphor of patient as traveler in a foreign country may make the ways in which social support plays a role in facilitating access to health care more apparent. Social support and social networks are tremendously beneficial when traveling to another country. Friends and family can coach novice travelers on the process of applying for a passport and visa, provide advice on how to find transportation and, in some cases, travel with an individual to act as a translator. Thus, accessing and navigating the health-care system without a social network of coaches, guides, and “translators” might present significant challenges to patients, particularly those living with chronic diseases that affect functional abilities. Williams posited that psychosocial factors (including social networks or ties) and medical care are “viewed as linked to social status and as mediators of the association between SEC [socioeconomic status] and health outcomes.”24 Although the literature appears to support the assumption that social support has an impact on aspects of health-care access, the direct association between social support and access to health care as a broad construct has

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not been sufficiently explored, particularly in ESRD patients. This lack of research results, in part, from the difficulty of disentangling the construct of access to care from those of insurance status, compliance, and patient satisfaction with care. Because access to care is a multidimensional construct that consists of a patient’s ability to enter the health-care system, find and communicate with a trusted health-care provider who can meet the patient’s needs, and get to the location where care is being provided, measuring the effect of social support on overall access to care in patients with kidney disease is a complex process that has not been sufficiently explored. Research has tended to focus on one aspect or indicator of health-care access, rather than on social support and health-care access as a whole. For example, Gordon et al 25 discovered that transportation issues were primary reasons that patients skipped hemodialysis treatment, but social support was not explored in the study, which made a determination of what role, if any, the presence or absence of social support played in patients’ transportation difficulties difficult. We explored the multidimensional aspects of social support and access to care more fully and demonstrated a relation among ESRD patients between patient satisfaction with staff and level of social support. We correlated this relation with improved attendance/compliance.26 Additional research with ESRD patients is needed to examine the relations between social support and access to care, conceptualized broadly as a construct that comprises (1) insurance status, (2) patient’s perceived and actual ability to afford care, (3) presence of a primary-care provider, (4) patient satisfaction with provider/care, (5) patients’ perception of accessibility of care (ie, transportation, geographic accessibility issues, etc), and (6) utilization of care. Until such research is conducted, a determination of whether and how social support directly affects access to health care as a whole, especially in patients with kidney disease, is difficult to make. Social Support and Depression Depression is a common psychiatric condition that coexists with and complicates a wide

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variety of chronic diseases. Patients with chronic illness experience permanent lifestyle changes, social isolation, and loss of independence and develop lower perceptions of self, all of which may contribute to the development of depression.27,28 Depression, in turn, may lead to decreased energy level, loss of appetite, and less interest in activities, including decreased willingness and ability to care for oneself. Furthermore, increased symptoms of depression are associated with increased anxiety, tendencies toward social isolation, worsening physical symptoms of illness, worsening shortness of breath in patients with heart failure and chronic pulmonary disease, and higher rates of morbidity and mortality from cardiovascular disease.19,29,30 Social support has been shown to ameliorate depressive symptoms in patients with chronic disease by both direct means, in which support is actually provided either emotionally or functionally, and perceived means, in which the feeling of not being isolated or lonely is protective.27,30 This observation is especially true for those patients with spousal or partner support.30 Depression is thought to be the most common psychiatric condition in ESRD patients,31-36 although its exact prevalence remains unknown, partly because the diagnosis of depression in such patients is potentially confounded by the similarity of the somatic symptoms of depression with the physical symptoms of uremia.31-33,37,38 Depression also causes significant morbidity. ESRD patients have higher hospitalization rates for depression than that seen in other chronic illnesses, lower health-related quality of life (HRQOL) scores, worse nutrition, and decreased levels of compliance.22,31,39-43 Patients with ESRD experience the additional stress of undergoing a time-consuming, long-term therapy that affects their ability to work, travel, and interact with their friends and families,7,31 and they experience a decline in mental and physical abilities, including impaired sexual function, all of which may contribute to the pathogenesis and extent of depression.31-33 In addition, we have shown an association between depression and mortality in patients with ESRD.20 However, large interventional studies that examine the effects of social support

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on depression in ESRD patients continue to be lacking.7 Guzman and Nicassio44 examined negative and positive illness schemas by use of a 3-part scoring system that evaluated patients’ perceptions of illness and their relation with disease severity and level of social support as predictors of depression in 109 patients with ESRD. They found, as expected, that a negative perception of health was associated with depression, whereas a positive perception of health was negatively associated with depression. Greater disease severity was related to poorer perception of illness. Disease severity, however, was not independently predictive of depression. Social support was associated with positive illness-schema scores, and lower levels of social support were associated with increased levels of depression. Furthermore, a statistically significant association between social support and depression was found, which was unrelated to illness schema. Low levels of social support could, therefore, be viewed as a risk factor for depression and a target for early intervention by clinicians. Social Support and Compliance Compliance, defined by Haynes et al”45 refers to “a patient’s behavior in respect to taking medications, following diets, or executing lifestyle changes, that coincide with medical or health advice.” Patients undergoing long-term dialysis must adhere to several lifestyle and dietary modifications in addition to undergoing a time-consuming chronic therapy, all of which may be potential areas associated with noncompliance.46,47 Several studies have established a correlation between social support and improved compliance with a medication regimen, lifestyle, or dietary modification or self-care in patients with chronic diseases such as HIV infection, diabetes mellitus, and hypertension.13,16,48-51 This relation has also been examined in ESRD patients with variable findings.7,22,26,46,47,52 Although we did not find an association between social support and behavioral compliance in our study of hemodialysis patients in an urban setting, we did quantify the level of behavioral compliance of patients by measuring the percent time compliance, percent attendance, and the total time compliance.22,47 Using these measures in a subse-

quent study, we were able to demonstrate a relation between patient satisfaction with staff and level of social support, which correlated with improved attendance, higher patient protein-catabolic rates (PCR), and higher serum albumin levels.26 Adoption of these indicators of behavioral compliance may allow for a means of standardization in future studies of compliance in ESRD patients. More recent studies that evaluated the relation between social support and compliance in ESRD patients have again shown disparate results. In a subpopulation of the Choices of Healthy Outcomes in Caring for End-Stage Renal Disease Study (CHOICE), Unruh, et al53 prospectively followed 739 incident hemodialysis patients and examined the hypothesis that inadequate adherence to therapy is associated with lower quality of life, diminished social support, lower patient satisfaction, and maladaptive health behaviors. Greater levels of noncompliance were also thought to be associated with decreased survival and lower likelihood of kidney transplantation. In addition to the biologic markers of serum potassium and phosphate levels, compliance was measured by calculating the number of skipped treatments divided by the number of planned treatments during the follow-up period, with a cutoff of noncompliance at a level greater than 3%. They showed that noncompliance was significantly more frequent in patients who were younger, African American, current smokers, and users of illicit drugs, which is consistent with data previously published.22,47,52,54 Noncompliance was also associated with a 69% increased risk of death, which is consistent with but higher than that reported in previous studies.22,47,54-56 No difference in compliance was found with regard to gender, education, employment, comorbid disease, level of social support, quality of life, or satisfaction with care. In another study, Berman et al57 examined religious and spiritual beliefs in 74 hemodialysis patients and their association with social support, satisfaction with care, satisfaction with life, depression, and compliance. In this study, compliance was measured by determining the number of skipped dialysis sessions over a 4-month period, as well as recording the absolute number of shortened

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sessions. They found no relation between religious activity and compliance; however, higher religiosity scores were associated with greater satisfaction with life scores, satisfaction with medical care scores, and increased levels of social support. We have previously shown positive correlations between greater spiritual beliefs and the level of social support, quality of life scores, and satisfaction with care. However, we did not measure behavioral compliance in this study.21 Given these established relations and the notion that higher quality of life and satisfaction with care scores would be associated with improved compliance, additional, large-scale, prospective studies should be performed to explore this issue further. A recent European study examined risk factors for noncompliance in kidney transplant patients.58 Noncompliance in these patients can be defined as major, which may result in rejection and eventual graft loss, or subclinical, which does not manifest itself as an episode of rejection or graft loss. A total of 139 patients were enrolled in the study. Most were middle-aged men and recipients of cadaveric organs. The most common immunosuppressive regimen included cyclosporine, mycophenolate mofetil, and prednisone. Compliance was measured by patient and physician questionnaires, as well as by direct measurement of cyclosporine levels. Their results showed that adverse effects of immunosuppressive medications were the strongest predictor of noncompliance. Male gender and lower self-reported health scores were additional risk factors. Interestingly, lower level of social support was a significant risk factor for noncompliance in this population. Those patients with a lower level of social support had a 4.5 times greater likelihood of noncompliance than those with greater levels of support. These findings are important, as social support represents a potentially modifiable risk factor in kidney transplant recipients that may allow prolongation of graft survival and prevention of rejection. Identification of patients at risk before, or shortly after, transplantation may allow clinicians an opportunity for early intervention to help maintain graft survival.

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Marriage and Chronic Disease Much research has been conducted on the role of marriage and social support provided by spouses to patients with chronic disease. For many adults, their primary relationship is with a spouse or significant other.59 For married individuals, a primary source of social support could be their spouse or significant other acting as a caregiver, confidant, and source of emotional support. If greater social support is associated with improvements in depression, compliance, and survival, then married individuals should have improved health outcomes compared with unmarried individuals. Alternatively, marriages associated with interpersonal conflict might be associated with poorer psychological status of the partners. Married individuals have lower rates of depression and lower rates of mortality than do unmarried individuals.59-62 Furthermore, being married in itself is not what seems to be beneficial for health, but rather the quality of the marriage may be the important factor. Individuals who are unhappy in their marriage or engage in more frequent marital conflict may have higher levels of stress and experience direct physiologic changes, which may lead to worse health outcomes than those individuals who are happily married.59,61,63-67 Recent studies support this association between marital status and survival in patients with chronic diseases such as breast cancer and congestive heart failure.68,69 We examined the role of a stable dyadic relationship and its affects on health outcomes in ESRD patients treated with hemodialysis.67 Of 295 patients who were recruited as part of a larger study,22 174 were identified as being involved in a dyadic relationship, defined as being with a spouse or partner for 6 months or longer. We used the Dyadic Adjustment Scale (DAS) to evaluate the patient’s marital satisfaction. We found that for men, dyadic adjustment parameters correlated only with increased age. Older men experienced less relationship conflict. For women, however, greater dyadic satisfaction correlated with higher levels of attendance at hemodialysis sessions. In addition, greater relationship conflict was associated with lower levels of Kt/V. Furthermore, women who experienced lower levels of sat-

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isfaction with the relationship and greater dyadic conflict also had higher levels of depression, worse illness perception, and lower levels of social support. Most importantly, however, we found strong associations between dyadic satisfaction and mortality. An increase of 1 standard deviation in dyadic satisfaction scores was associated with a 29% decrease in relative mortality risk.67 An increase of 1 standard deviation in dyadic conflict scores was associated with a 46% increase in mortality.67 These results further support the theory that marital satisfaction has robust effects on health outcomes in CKD patients, especially women. An unhappy marriage and increased marital conflict may have serious consequences for health in ESRD patients, including death. Further research should be done to examine these relationships and to investigate why women seem particularly at risk. Social Support and Immune Function The mechanisms by which social support affect patients remain unknown. Evidence, however, suggests that social support may have direct physiologic effects on health through interactions with the cardiovascular, endocrine, and immune systems.6 Uchino et al6 examined several studies involving such relationships, and found that a higher level of social support, particularly familial support, was associated with lower blood pressures in both normotensive and hypertensive patients, as well as increased immune system function as measured by natural killer (NK) cell activity. The data that established a link between social support and catecholamine levels was variable and, overall, inconclusive.6 These findings were confirmed and expanded on in other reviews that examined the physiologic influences of spousal support, which demonstrated that poorer marital quality is associated with higher blood pressure, higher circulating levels of catecholamines, and worse immune function, as reflected by decreased NK cell activity and increased Epstein-Barr virus (EBV) antibody titers.59,65,66,70,71 More recently, higher levels of social support were shown to be associated with increased NK cell activity, as well as interferon gamma (IFN-␥) levels and decreased IL-4 levels, which favors

a Th1 (cellular) immune response.72 These results suggest that social support may exert its immunoprotective effects through innate and cell-mediated immune responses. Furthermore, Marucha et al 73 recently found that increased social activity and greater satisfaction with a partner relationship was associated with increased circulating levels of tumor necrosis factor alpha (TNF-␣) in patients with stage II or III breast cancer. In ESRD patients, we have shown an association between depression and higher levels of perceived marital conflict with increased circulating levels of proinflammatory cytokines in women.67,74 Higher cytokine levels, in turn, were associated with mortality in this patient population. In contrast, greater marital satisfaction was associated with lower levels of marital conflict and a decreased mortality risk in women.67 Why this association was only true for women in our study remains unclear. However, these results suggest that social support, by means of greater marital satisfaction, may exert a survival advantage through immunomodulatory mechanisms. Additional studies should be performed to further investigate these findings.

Social Support and Survival Although the exact mechanisms underlying its protective effects remain unclear, the evidence for an association between social support and mortality in patients with chronic disease continues to expand. Higher levels of social support and social integration have been associated with lower rates of mortality in patients with chronic diseases such as breast cancer, congestive heart failure, and cardiovascular disease.18,75-79 The relation between social support and survival in ESRD patients has not been studied as extensively. An early study by Friend et al80 demonstrated a statistically significant survival advantage among those ESRD patients who participated in peer-driven group-support sessions that focus on coping skills and group discussions on stress and lifestyle adjustments compared with those patients who elected not to participate. These findings were encouraging; however, the retrospective nature of the study and other methodologic concerns make the mean-

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ing of these results difficult to interpret. In a subsequent study, McClellan et al 81 showed that those patients capable of giving higher levels of social support survived longer than those who were unable to give social support. No association was seen between survival and amount of social support received by patients in this study. The association between increased giving of social support and survival may be related to better physical function in patients capable of providing social support. In our study involving hemodialysis patients in an urban setting, we prospectively followed 295 primarily African-American patients over approximately 4 years.22 Study patients were recruited from the George Washington University Medical Center (GWUMC), Howard University Medical Center (HUMC), and Washington Veterans Affairs Medical Center (VAMC) dialysis units. We measured disease severity, nutritional markers, and standard parameters of dialysis, such as PCR, Kt/V, and dialyzer type, level of depression, perceived social support, perception of illness effects, quality of life indicators, and behavioral compliance parameters. Level of depression was assessed by use of the Beck Depression Inventory (BDI) and Cognitive Depression Index (CDI) scores. Social support was measured by use of the Multidimensional Scale of Perceived Social Support (MSP),82 which assesses a patient’s level of social support from family, friends, and special persons. From these measures, we derived a total social support score (MSPTOT), which was the sum of the 3 factor scores reported by the patient. Our results demonstrated, as expected, that increased age and severity of illness were associated with higher mortality. Patients with higher serum albumin concentrations had lower mortality risk. Increased compliance as measured by percent time compliance and total time compliance was associated with a decrease in relative mortality risk. After age, severity of illness, serum albumin level, and dialyzer type were controlled for, an increase of 1 standard deviation in perception of social support was associated with a 20% decrease in relative mortality risk. Level of depression and Kt/V were not associated with mortality in this study. Our findings confirm that psychosocial fac-

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tors, particularly social support, do indeed play a major role in affecting outcomes in primarily African-American ESRD patients. The improvement in mortality may result indirectly from the social support’s effects on level of depression and compliance or directly from improvements in access to care or from the physiologic mechanisms described previously. Despite these results, large-scale studies have not been performed to assess whether the mortality effects of social support extend to other ESRD and CKD populations and patients with other chronic illnesses. Most of the patients in our studies were African American, and the results may not be generalizable to other populations. Such issues require further study.

Conclusion Social support is an important modifiable risk factor in a variety of chronic diseases, including ESRD. Improvements in social support among ESRD patients may lead to reductions in levels of depressive affect and may enhance patient perceptions of their quality of life. This outcome may lead to improved survival rates by increasing patient compliance with prescribed therapy. Nephrologists and other allied health professionals should pay particular attention to a patient’s social support system and should try to institute changes at the dialysis unit that may enhance a patient’s perception of support. The associations between social support and outcomes should be studied in diverse populations of patients in all stages of chronic kidney disease. A randomized controlled trial, examining a socialsupport group intervention in dialysis patients, is urgently needed to evaluate potential outcomes.

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